#include <REGX52.H>

void Delay(unsigned int xms)
{
	unsigned char data i, j;
	while(xms)
	{
		i = 2;
		j = 239;
		do
		{
			while (--j);
		} while (--i);
		xms--;
	}
}

void main()
{
	unsigned char LEDNum=0;
	P2=~0x01;
	while(1)
	{
		if(P3_1==0)
		{
			Delay(20);
			while(P3_1==0);
			Delay(20);
			LEDNum++;
			LEDNum%=8;
			P2=~(0x01<<LEDNum);
		}
		if(P3_0==0)
		{
			Delay(20);
			while(P3_0==0);
			Delay(20);
			LEDNum--;
			LEDNum%=8;
			P2=~(0x01<<LEDNum);
		}
	}
}